Make sure that when you exit Outlook that the outlook process is not hung up while closing. If you open task manager and look at the PROCESSES tab, see if Outlook appears there (again this is after you've exited the program and waited a few seconds for it to do its thing). If it does, then you might have a toolbar or add-in that stopping it from closing correctly. If you do find it still running, you can end the process and wait for it to no longer appear in the task manager. Once that happens, try to restart outlook and see what happens.